Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Fortinet (NASDAQ:FTNT) jumped to an 11% gain after Tuesday's opening bell, but have since settled into a still-strong pop of roughly 8% as of this writing. Investors are cheering the cybersecurity company's first-quarter earnings beat, which was reported after Monday's close.

So what: Fortinet's first-quarter revenue was up 26% year-over-year to $212.9 million thanks to a 36% year-over-year increase in quarterly billings to $254.3 million. Adjusted earnings were $0.08 per share, and free cash flow came in at $59.7 million for the quarter. Both top- and bottom-line results bested Wall Street's projections, which had called for $205.2 million in revenue and $0.06 in adjusted EPS. Adjusted EPS fell from an $0.11-per-share result in the year-ago quarter on weaker operating margins, but free cash flow rose 20% year-over-year, largely due to Fortinet's reduced capital expenditures.

Looking ahead, Fortinet now expects second-quarter revenue to range from $224 million to $228 million, resulting in adjusted EPS of $0.08 to $0.09. Fortinet also raised its full-year revenue guidance from an earlier $915 million to $925 million range to a new range of $935 million to $940 million. The company's second-quarter EPS guidance falls below Wall Street's $0.11 projection, but both second-quarter and full-year revenue guidance ranges now handily best the Street's projections of $222.1 million and $926.1 million, respectively.

Now what: Fortinet appears to be entering the high-burn phase of a fast-growing software enterprise, as it's now plowing much of its money back into business development to propel faster top-line growth. Despite this, Fortinet remains profitable, though at a P/E of 250, it's certainly not priced at bargain rates. The company's price-to-free-cash-flow ratio is much more reasonable at 38.7 (prior to yesterday's report) for a fast-growing company, and the reasonable rate of today's pop offers investors plenty of reasons to stick around.

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